Biologically Active Secondary Metabolites from Fungi. 12. Oidiolactones A−F, Labdane Diterpene Derivatives Isolated from Oidiodendron truncata

Abstract

Two known (1 and 2) and four new (3-6) diterpenes named oidiolactones A-F, respectively, and the antibiotic cladosporin were isolated from the fungus Oidiodendron truncata. The structure determination was mainly based on 1D and 2D NMR spectroscopy. The structures of compound 4, displaying an equilibrium between open-chain and cyclized form, and of cladosporin were confirmed by X-ray analysis.